• Korean Journal of Microbiology
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• v.38 no.3
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• pp.192-197
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• 2002

Fluorescent in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes was used to compare the community structures of free-living and aggregated bacteria at thawing period in Lake Baikal. Targeted groups were Eubacteria, $\alpha$-, $\beta$-, $\gamma$- proteobacteria groups, Cytophaga-Flavobacterium group and Planctomycetales. Total bacterial numbers of free-living bacteria were ranged from $0.2{\times}10^6\cells{\cdot}ml^-1$ to $3.2{\times}10^6\cells{\cdot}ml^-1$, which were decreasing with depth, while the aggregated bacterial numbers were dramatically increasing from $0.4{\times}10^4 to 3.3{\times}10^4 \cells{\cdot}ml^-1$ with depth. The ratios of EUB probe binding cells to DAPI counts were ranged from 52.3 to 74.1% in free-living bacteria, and from 39.6 to 66.7% in the aggregated bacteria, respectively. Community structures of the aggregated bacteria were very different from each free-living bacteria at every depth. At 25 m depth, where the chlorophyll a concentration was highest, both structures were quite different from those of surface layers, rendering the fact that the community structures might be affected by phytoplankton. The vertical profile of community structure of aggregated bacteria is particular. The proportion of $\beta$-proteobacteria group was increasing with depth and it was 51.8% at 100 m, but the dominant group was $\gamma$-pro-teobacteria group at 250 m. Taken together, the biodiversity and succession of aggregated bacteria are quite different from free-living bacteria.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.133-136
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• 2013

The purpose of this study was to compare a conventional culture method and real-time PCR for the detection of Yersinia enterocolitica (Y. enterocolitica) in sausage and in vegetable salad. Food samples inoculated with Y. enterocolitica were enriched in peptone-sorbitol bile-broth, and swabs were then streaked onto cefsulodin-irgasan-novobiocin agar. Biochemical tests for suspected colonies were performed with an API 20E strip. In parallel, real-time PCR was performed, targeting the 16S rRNA gene using 1 mL of enrichment broth. In sausage, the number of positive samples detected by culture method (49 out of 60) was similar (p>0.05) with that of real-time PCR (50 out of 60). However, the number of positive samples of real-time PCR (26 out of 60) was significantly higher (p<0.05) than that of the conventional culture method (6 out of 60) in vegetable salad. Real-time PCR could be an effective screening tool for detecting Y. enterocolitica, particularly in food samples with high levels of background flora, such as a vegetable salad.

• Journal of Food Hygiene and Safety
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• v.29 no.1
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• pp.40-46
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• 2014

We have screened Bacillus strains suitable for the fermentation of soybean products with respect to the control of Bacillus cereus and the reduction of biogenic amines. Of 26 isolates, a strain named as the SCK A08 carried antimicrobial activity against B. cereus and Staphylococcus aureus, major food poisoning species in soybean products. PCR analysis revealed that the SCK A08 strain did not contain genes for Bacillus cereus toxins including nonhemolytic enterotoxin, hemolytic enterotoxin, cytotoxin K, cereulide and certrax. The SCK A08 strain could degrade histamine, tyramine, putrescine, and cadaverine by 67.41%, 76.59%, 57.32%, and 50.69%, respectively, during fermentation in cooked soybeans containing 0.5% (w/w) of each biogenic amine. The morphological and biochemical properties and phylogenetic relationships based on 16S rRNA gene sequences indicated that the isolate was most closely related to Bacillus licheniformis. Use of the strain SCK A08 would be a potential measure to overcome two hygienic problems that were frequently faced during manufacture of traditionally fermented soybean products.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.501-508
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• 2007

In order to develop a new starter for fermented milk, Lactobacillus plantarum M23 was isolated from raw milk and investigated for physiological characteristics. It showed good tyrosinase inhibitory activity compared with commercial lactic acid bacteria. The optimum growth temperature of Lactobacillus plantarum M23 was $40^{\circ}C$ and cultures took 17 hr to reach pH 4.3. Lactobacillus plantarum M23 showed more sensitivity to Penicillin-G, Oxacillin, Novobiocin, Chloramphenicol in a comparison of 12 different antibiotics, and showed most resistance to Vancomycin. It showed higher leucine arylamidase and ${\beta}-galactosidase$ activities compared to 16 other enzymes. It was comparatively tolerant to bile juice and able to survive at pH 2 for 3 hours. It showed high resistance to Escherichia coli, Salmonella typhimurium and Staphylococcus aureus with rates of 77.8%, 86.5% and 83.8%, respectively. Based on these and previous results, Lactobacillus plantarum M23 could be an excellent starter culture for fermented milk with high resistance to melanin.

• Journal of Chitin and Chitosan
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• v.23 no.4
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• pp.277-284
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• 2018

In this study, we investigated the anti-allergic effect of the ethyl acetate fraction of Ecklonia cava (EC-EtoAc) on the immunoglobulin E (IgE)/bovine serum albumin (BSA)-mediated activation of bone marrow-derived cultured mast cells (BMCMCs). We revealed that the $62.5{\mu}g/ml$ of EC-fractions ($EC-CHCl_3$, EC-Hexane and EC-EtoAc) inhibited IgE/BSA-activated ${\beta}$-hexosaminidase release from BMCMCs without cytotoxicity. Especially, EC-EtoAc showed the higher ${\beta}$-hexosaminidase release than the others. Also, EC-EtoAc reduced the expression levels of cytokines such as interleukin (IL)-$1{\beta}$, IL-4, IL-5, IL-6, IL-10, IL-13, interferon (IFN)-${\gamma}$ and tumor necrosis factor (TNF)-${\alpha}$ and a chemokine, thymus- and activation-regulated chemokine (TARC), compared to the only IgE/BSA-treated BMCMCs. Furthermore, EC-EtoAc significantly prevented the binding of IgE to Fc epsilon receptor $(Fc{\varepsilon}R)I$ and reduced the $Fc{\varepsilon}RI$ expression on the sensitized BMCMCs. Taken together, these results suggest that E. cava may be the natural agent with beneficial potentials for the treatment of type I allergic diseases induced by mast cell activation.

• Journal of Chitin and Chitosan
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• v.23 no.4
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• pp.285-292
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• 2018

In this study, for the purpose of decomposing food waste, the strain was screened from traditional fermented food and soils. The enzyme activity (protease, amylase, cellulase, lipase) experiment was carried out using the paper disc method in 212 strains isolated from 5% NaCl media. Among them, only the strains having enzyme activity of more than 2 (soil) or more than 4 (traditional fermented food) with the halozone of enzyme activity of 15 mm or more were selected first, and microorganism identification through 16S rRNA sequencing was performed. Finally, were identified such as Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus siamensis, Bacillus licheniformis, Bacillus aquimaris, Bacillus megaterium, Bacillus koreensis, Bacillus stratoshericus, Bacillus aryabhattai, Bacillus safensis, Marinobacter hydrocarbonoclasticus. 11 species of mixed strains were confirmed that the culture time was 24 hours, the incubation temperature was $30^{\circ}C$ and the optimum pH was 7.0. In order to confirm the degree of decomposition of standard food wastes (100 g) by treating 11 kinds of mixed strains (25%), solid content of more than $2000{\mu}m$ was determined to be 103 g for the sterilized water group and 18 g for the mixed strains group. And the rest was decomposed to a size of less than $2000{\mu}m$.

• Experimental and Molecular Medicine
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• v.51 no.2
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• pp.1.1-1.14
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• 2019

Hypoxia-inducible factor-$1{\alpha}$ ($HIF-1{\alpha}$) mediates tumor cell adaptation to hypoxic conditions and is a potentially important anticancer therapeutic target. We previously developed a method for synthesizing a benzofuran-based natural product, (R)-(-)-moracin-O, and obtained a novel potent analog, MO-460 that suppresses the accumulation of $HIF-1{\alpha}$ in Hep3B cells. However, the molecular target and underlying mechanism of action of MO-460 remained unclear. In the current study, we identified heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1) as a molecular target of MO-460. MO-460 inhibits the initiation of $HIF-1{\alpha}$ translation by binding to the C-terminal glycinerich domain of hnRNPA2B1 and inhibiting its subsequent binding to the 3'-untranslated region of $HIF-1{\alpha}$ mRNA. Moreover, MO-460 suppresses $HIF-1{\alpha}$ protein synthesis under hypoxic conditions and induces the accumulation of stress granules. The data provided here suggest that hnRNPA2B1 serves as a crucial molecular target in hypoxiainduced tumor survival and thus offer an avenue for the development of novel anticancer therapies.

• Journal of Microbiology and Biotechnology
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• v.29 no.10
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• pp.1644-1655
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• 2019

Saccharomyces cerevisiae (S. cerevisiae) and glucagon-like peptide-2 (GLP-2) have been employed to improve the intestinal development of weaned animals. The goal of this study was to determine whether either exogenous S. cerevisiae or GLP-2 elicits major effects on fecal microbiotas and cytokine responses in weaned piglets. Ninety-six piglets weaned at 26 days were assigned to one of four groups: 1) Basal diet (Control), 2) empty vector-harboring S. cerevisiae (EV-SC), 3) GLP-2-expressing S. cerevisiae (GLP2-SC), and 4) recombinant human GLP-2 (rh-GLP2). At the start of the post-weaning period (day 0), and at day 28, fecal samples were collected to assess the bacterial communities via sequencing the V1-V2 region of the 16S-rRNA gene, and piglets' blood was also sampled to measure cytokine responses (i.e., IL-$1{\beta}$, TNF-${\alpha}$, and IFN-${\gamma}$). This study revealed that, on the one hand, although S. cerevisiae supplementation did not significantly alter the growth of weaned piglets, it induced increases in the relative abundances of two core genera (Ruminococcaceae_norank and Erysipelotrichaceae_norank) and decreases in the relative abundances of two other core genera (Lachnospiraceae_norank and Clostridiale_norank) and cytokine levels (IL-$1{\beta}$ and TNF-${\alpha}$) (p < 0.05, Control vs EV-SC; p < 0.05, rh-GLP2 vs GLP2-SC). On the other hand, GLP-2 supplementation had no significant influence on fecal bacterial communities and cytokine levels, but it produced better body weight and average daily gain (p < 0.05, Control vs EV-SC; p < 0.05, rh-GLP2 vs GLP2-SC). Therefore, altered fecal microbiotas and cytokine response effects in weaned piglets were due to S. cerevisiae rather than GLP-2.

• Food Science and Preservation
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• v.18 no.6
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• pp.973-979
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• 2011

The grape cultivar Campbell Early has high levels of malic acid as well as tartaric acid. The high concentration of total acid in the Campbell Early wine is a critical aspect of the wine's sensory characteristics. To prevent the deterioration of the wine's quality, which is caused by the strong sour taste derived from the raw material in wine making, the deacidification factor was investigated via carbonic maceration under different temperature conditions, especially in the presence or absence of malolactic bacteria. Based on the results of the presence test of the malolactic bacteria during carbonic-maceration treatment, Lactobacillus brevis, Lactobacillus plantarum, and Streptococcus thermophilus were characterized morphologically and were identified via biochemical tests and 16S-rRNA-gene-sequencing analysis. The isolated strains were found not to consume malic acid and to produce lactic acid. Moreover, these strains were consumed as soluble solids. The isolated strains are popularly known as lactic-acid bacteria and should have produced lactic acid from glucose. The Oenococcus oeni of the malolactic bacteria was not isolated. These results showed that the isolated strains are not deacidified during carbonic-maceration treatment.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1169-1175
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• 2011

The soil chemical properties, microbial community structures and biochemical properties of lettuce or cucumber-cultivated greenhouse soil samples were analyzed to assess soil health and characterize microbial distribution in 8 locations in Korea. Although most of chemical properties were within the soil management guidelines, the available phosphate, and the contents of exchangeable potassium and calcium were higher than those of recommended levels. In the culture-dependent analysis, 841 bacterial strains were isolated from the greenhouse soils and were identified at the genus level by 16S rRNA gene sequences analysis. The dominant bacterial genera were Bacillus (35.7%), Microbacterium (9.3%), Arthrobacter (5.7%) and Lysobacter (5.1%). The abundance of pseudomonads was highly variable depending on the soil samples. In the culture-independent analysis, soil microbial community was investigated by using phospholipid fatty acid (PLFA) method. Principal component analysis (PCA) showed that a specific grouping for microbial community structure in the greenhouse soils was not observed based on cultivated crops and investigated sites. The results revealed that the greenhouses soils examined are relatively sound managed in terms of soil chemical contents and microbial properties.